Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.3 (KDE 4.3.3)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-15-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
After going to the Desktop Search in System settings there was a notification about suggestions to install extra packages. I clicked on the icon that appeared in the systray (or what i's called now :) and the installation of soprano-backend-sesame went fine but the plasma-desktop crashed.
BTW: It's not very intuitive with the icon in the systray. It took me a while to realize that it had appeared after the notification had come and gone again.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb77fe700 (LWP 1449))]

Thread 2 (Thread 0xaba63b70 (LWP 1450)):
#0  0x00903422 in __kernel_vsyscall ()
#1  0x00423e15 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x009dd78d in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0x0048fe67 in QWaitConditionPrivate::wait (this=0xa450568, mutex=0xa450564, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  QWaitCondition::wait (this=0xa450568, mutex=0xa450564, time=4294967295) at thread/qwaitcondition_unix.cpp:159
#5  0x00e7d922 in QHostInfoAgent::run (this=0xa450558) at kernel/qhostinfo.cpp:260
#6  0x0048ee32 in QThreadPrivate::start (arg=0xa450558) at thread/qthread_unix.cpp:188
#7  0x0041f80e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#8  0x009d07ee in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb77fe700 (LWP 1449)):
[KCrash Handler]
#6  0x014593f3 in Plasma::ExtenderItem::config (this=0x9bcc0a0) at ../../plasma/extenderitem.cpp:153
#7  0x0145b16d in Plasma::ExtenderItem::isGroup (this=0x9bcc0a0) at ../../plasma/extenderitem.cpp:341
#8  0x014511cf in Plasma::Extender::isEmpty (this=0x9d60a90) at ../../plasma/extender.cpp:717
#9  0x01451237 in Plasma::ExtenderPrivate::updateEmptyExtenderLabel (this=0x9d606d8) at ../../plasma/extender.cpp:681
#10 0x01451983 in Plasma::Extender::itemAddedEvent (this=0x9d60a90, item=0xb314cc0, pos=...) at ../../plasma/extender.cpp:432
#11 0x014509d7 in Plasma::ExtenderPrivate::addExtenderItem (this=0x9d606d8, item=0xb314cc0, pos=...) at ../../plasma/extender.cpp:546
#12 0x0145bef1 in Plasma::ExtenderItem::setExtender (this=0xb314cc0, extender=0x9d60a90, pos=...) at ../../plasma/extenderitem.cpp:247
#13 0x0145cd9a in ExtenderItem (this=0xb314cc0, hostExtender=0x9d60a90, extenderItemId=0) at ../../plasma/extenderitem.cpp:129
#14 0x05117718 in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#15 0x0511caf0 in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#16 0x0511dedf in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#17 0x00595263 in QMetaObject::activate (sender=0x9d56730, from_signal_index=7, to_signal_index=7, argv=0xbf8f37f8) at kernel/qobject.cpp:3113
#18 0x00595ec2 in QMetaObject::activate (sender=0x9d56730, m=0x51397ac, local_signal_index=3, argv=0xbf8f37f8) at kernel/qobject.cpp:3187
#19 0x050f85e3 in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#20 0x050f99df in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#21 0x00595263 in QMetaObject::activate (sender=0xa4852b0, from_signal_index=6, to_signal_index=6, argv=0xbf8f3918) at kernel/qobject.cpp:3113
#22 0x00595ec2 in QMetaObject::activate (sender=0xa4852b0, m=0x5139804, local_signal_index=2, argv=0xbf8f3918) at kernel/qobject.cpp:3187
#23 0x050f9d33 in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#24 0x051088ec in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#25 0x051097fc in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#26 0x0058811d in QMetaMethod::invoke (this=0xbf8f3cec, object=0xa4852b0, connectionType=Qt::DirectConnection, returnValue=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., 
    val7=..., val8=..., val9=...) at kernel/qmetaobject.cpp:1522
#27 0x0058870f in QMetaObject::invokeMethod (obj=0xa4852b0, member=0x15598b2 "dataUpdated", type=Qt::AutoConnection, ret=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., 
    val7=..., val8=..., val9=...) at kernel/qmetaobject.cpp:1114
#28 0x01443c5f in QMetaObject::invokeMethod (this=0xaf7dc68, s=0xa25cc80, visualization=0xa4852b0, pollingInterval=0, align=Plasma::NoAlignment, immediateCall=true)
    at /usr/include/qt4/QtCore/qobjectdefs.h:403
#29 Plasma::DataEnginePrivate::connectSource (this=0xaf7dc68, s=0xa25cc80, visualization=0xa4852b0, pollingInterval=0, align=Plasma::NoAlignment, immediateCall=true)
    at ../../plasma/dataengine.cpp:607
#30 0x0144469b in Plasma::DataEngine::connectSource (this=0xaf7d450, source=..., visualization=0xa4852b0, pollingInterval=0, intervalAlignment=Plasma::NoAlignment) at ../../plasma/dataengine.cpp:94
#31 0x0510774b in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#32 0x0510981d in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#33 0x00595263 in QMetaObject::activate (sender=0xaf7d450, from_signal_index=4, to_signal_index=4, argv=0xbf8f4148) at kernel/qobject.cpp:3113
#34 0x00595ec2 in QMetaObject::activate (sender=0xaf7d450, m=0x157e1e4, local_signal_index=0, argv=0xbf8f4148) at kernel/qobject.cpp:3187
#35 0x014433a3 in Plasma::DataEngine::sourceAdded (this=0xaf7d450, _t1=...) at ./dataengine.moc:176
#36 0x01444980 in Plasma::DataEngine::setData (this=0xaf7d450, source=..., data=...) at ../../plasma/dataengine.cpp:210
#37 0x02ec1807 in ?? () from /usr/lib/kde4/plasma_engine_notifications.so
#38 0x02ec4a9d in ?? () from /usr/lib/kde4/plasma_engine_notifications.so
#39 0x00a697b4 in QDBusConnectionPrivate::deliverCall (this=0x9843630, object=0xaf74ae0, msg=..., metaTypes=..., slotIdx=9) at qdbusintegrator.cpp:891
#40 0x00a6a9c5 in QDBusConnectionPrivate::activateCall (this=0x9843630, object=0xaf74ae0, flags=273, msg=...) at qdbusintegrator.cpp:803
#41 0x00a6b234 in QDBusConnectionPrivate::activateObject (this=0x9843630, node=..., msg=..., pathStartPos=30) at qdbusintegrator.cpp:1347
#42 0x00a6b4da in QDBusActivateObjectEvent::placeMetaCall (this=0xb95b250) at qdbusintegrator.cpp:1464
#43 0x0058f5fe in QObject::event (this=0xaf7d450, e=0xb95b250) at kernel/qobject.cpp:1111
#44 0x05b1df54 in QApplicationPrivate::notify_helper (this=0x9869838, receiver=0xaf7d450, e=0xb95b250) at kernel/qapplication.cpp:4056
#45 0x05b2567c in QApplication::notify (this=0x98429c0, receiver=0xaf7d450, e=0xb95b250) at kernel/qapplication.cpp:3603
#46 0x0115314a in KApplication::notify (this=0x98429c0, receiver=0xaf7d450, event=0xb95b250) at ../../kdeui/kernel/kapplication.cpp:302
#47 0x0057f6cb in QCoreApplication::notifyInternal (this=0x98429c0, receiver=0xaf7d450, event=0xb95b250) at kernel/qcoreapplication.cpp:610
#48 0x005802b2 in QCoreApplication::sendEvent (receiver=0x0, event_type=0, data=0x97f2e48) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#49 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x97f2e48) at kernel/qcoreapplication.cpp:1247
#50 0x0058047d in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1140
#51 0x005aa3ff in QCoreApplication::sendPostedEvents (s=0x986baa0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#52 postEventSourceDispatch (s=0x986baa0) at kernel/qeventdispatcher_glib.cpp:210
#53 0x0039ce78 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#54 0x003a0720 in ?? () from /lib/libglib-2.0.so.0
#55 0x003a0853 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#56 0x005aa02c in QEventDispatcherGlib::processEvents (this=0x9869628, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#57 0x05bbebe5 in QGuiEventDispatcherGlib::processEvents (this=0x9869628, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#58 0x0057dc79 in QEventLoop::processEvents (this=0xbf8f4db4, flags=) at kernel/qeventloop.cpp:149
#59 0x0057e0ca in QEventLoop::exec (this=0xbf8f4db4, flags=...) at kernel/qeventloop.cpp:201
#60 0x0058053f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#61 0x05b1ddd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#62 0x084c980d in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#63 0x0804dde1 in launch (argc=<value optimized out>, _name=<value optimized out>, args=<value optimized out>, cwd=0x0, envc=0, envs=0x980c0e0 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x80511a5 "0") at ../../kinit/kinit.cpp:677
#64 0x0804ea35 in handle_launcher_request (sock=<value optimized out>, who=<value optimized out>) at ../../kinit/kinit.cpp:1169
#65 0x0804eeac in handle_requests (waitForPid=<value optimized out>) at ../../kinit/kinit.cpp:1362
#66 0x0804fbaf in main (argc=2, argv=0xbf8f5614, envp=0xbf8f5620) at ../../kinit/kinit.cpp:1793

This bug may be a duplicate of or related to bug 197016

Reported using DrKonqi